Carton closure flap construction



Jan. 30, 1962 M. L. WAGAMAN CARTON CLOSURE FLAP CONSTRUCTION 2 Sheets-Sheet 1 Filed Feb. 24, 1960 INVENTOR. Merle L. Wagaman BY Attorney Jan. 30, 1962 M. WAGAMAN CARTON CLOSURE FLAP CONSTRUCTION 2 Sheets-Sheet 2 Filed Feb. 24; 1960 INVENTOR. Merle L; Wagaman BY M Attorney United States Patent Ofiice 3,018,941 Patented Jan. 30., 1962 3,018,941 CARTON CLOSURE FLAP CONSTRUCTION Merle L. Wagaman, Lynwood, Calili, assignor to Fibreboard Paper Products Corporation, San Francisco, Callf., a corporation of Delaware Filed Feb. 24, 1960, Ser. No. 10,808 4 Claims. (Cl. 229-51) This'invention relates to car-tons, and more particularly to cartons made of paperboard having a closure flap which is adapted for adhesive union to a wall of the carton by means which facilitates ease of opening of the carton and obviates peeling of the outside face of such carton wall when the closure flap is pulled to open the carton.

Summarizing the invention, it comprises providing on the wall panel to which the closure flap is adapted to be adhesively secured, an area for adhesive union with the closure flap which is located between spaced apart lines of weakness partially penetrating the outer face of the wall panel and located between the ends thereof. These lines of weakness are also spaced from a free edge of the wall panel over which a cover panel to which the closure flap is hingedly connected, is adapted to overlie.

Desirably, the region of the outer face of the wall panel about the adhesive union area is provided with an adhesive repellent coating such as the printing ink commonly employed for applying a print pattern on the outside of the carton. When the closure flap is pulled to open the carton, material of the outer face of the carton between the lines of weakness will be removed substantially clean, thus leaving the outer face of the wall panel substantially unmarred otherwise.

From the preceding, it is seen that the invention has as its objects, among others, the provision of a closure arrangement for a carton closure flap which is of simple construction, facilitates ease of opening without substantially marring of a carton wall to which the closure flap is adhesively secured, and which can be economically manufactured.

Referring to the drawings which illustrate a form of carton in which the closure flap arrangement has been effectively employed:

FIG. 1 is a plan view looking at the outside face of the blank for the carton;

FIG. 2 is an enlarged fragmentary sectional view taken in a plane indicated by the line 2-2 in FIG. 1, the thickness of the ink repellent film being exaggerated to illustrate the arrangement more clearly;

FIG. 3 is an isometric view of the carton partially set up, illustrating how it is filled with contents;

FIG. 4 is an isometric view of the completely set up carton in its sealed state with contents therein;

FIG. 5 is an enlarged vertical section taken in a plane indicated by the line 5-5 in FIG. 4;

FIG. 6 is a fragmentary isometric view of the carton illustrating how the closure flap may be pulled open;

FIG. 7 is a transverse vertical sectional view taken in a plane indicated by line 7-7 in FIG. 6, with thejclosure flap pulled open;

FIG. 8 is a'fragmentary isometric view illustrating the closure flap completely open and the wall panel of the carton to which the closure flap had been secured, swung open for removal or insertion of contents into the carton;

FIG. 9 is a view similar to FIG. 8 illustrating how the closure flap and wall panel to which it had been secured, are positioned to reclose the carton;

FIG. 10 is a view similar to FIG. 9 illustrating the carton almost completely closed.

In greater detail, the closure flap sealing arrangement is illustrated on a well known type of carton adapted for the packaging of products, such as pics or cakes, wherein the carton is provided with a hinged wall that can be opened portion thereof has been cut for consumption. However, it is to be understood that the sealing arrangement can be employed in any type of carton wherein a closure flap hingedly connected to a cover panel of the carton is adhesively secured to an upstanding wall thereof.

In the type of carton illustrated, the blank is provided with score lines 1 to form various panels and flaps including a bottom cover panel 2 and a top cover panel 3 both hingedly connected to an intervening wall panel 4 adapted to form one upstanding side wall of the set up carton. Hingedly connected to the sides of the bottom andtop panels 2 and 3 are side wall forming panels 6 the adjacent ends of which are separated by cuts 7 from securing flaps 8 hingedly connected to the ends of wall panel 4.

-Hingedly connected at one end of the blank is wall panel 9 adapted to form the final wall of the set up carton; and at the opposite end of the blank a closure flap 11 is hingedly connected. Such closure is adapted for adhesive union to the outside face of panel 9. A tuck-in flap' 12 separated by a cut 13 from an end of adjacent side wall panel 6 is hingedly connected to each end of wall panel 9. An opening is provided partially in panel 3 and wall panel 4 which is covered by a light transmitting sheet 14, such as cellophane, adhesively secured to the inside face of the carton in a well known manner. The opening provides a window for viewing the contents of the carton.

' In collapsed state, closure flap 11 is adhesively secured over the outside face of wall panel 9 with all flaps 6, 8 and 12 extended. When the carton is to be filled with a product 15, such as a pie or cake, the wall panels 6 at one side of the carton are adhesively secured together in overlapped relationship in a conventional manner with flaps 8 and 12 on the inside, leaving the opposite side open for insertion of the product whereupon the panels at such opposite side are closed in a like manner as can be gathered from FIGS. 3 and 4.

In this connection, the tuck-in flaps 12 are not adhesively secured to Wall panels 6 in the completely closed carton. Hence, when closure flap 11 is pulled open, wallv panel 9 can be pivoted to an open position on its hing'e connection line for removal of the product; and when a portion of the product has been cut for consumption, the

remaining portion may be reinserted into the carton opening, and the carton can be reclosed by first closing closure flap 11 and then closing the wall panel 9 over the closure flap by insertion of the tuck-in flaps 12 into the carton, as can be seen from FIGS. 8, 9 and 10.

With prior closure flap sealing arrangements, when the closure flap was pulled to open the carton, peeling of material from the outside face of wall panel 9 was a problem as it caused an unsightly appearance after the closure flap was opened and reclosed in the manner described. Furthermore, particlesof the resultant peeling sometimes became enmeshed in the product; and frequently it was difiicult to pull the closure flap loose from its adhesive bond with the wall panel. 1

Means is provided to obviate such problem, comprising an area 16 on the outside face of wall panel 9 for adhesive union with 'the closure flap 11, which is located between spaced substantially parallel lines of weaknessv 17 partially penetrating the outer face of wall panel 9...

Such lines of weakness are desirably in the form of continuous cuts spaced apart about three-eighths to onefourth of an inch although this spacing distance is not particularly critical, Cuts 17 extend between opposite ends of wall panel 9 and desirably terminate closely adjacent to but short of such ends about three-sixteenth to one-fourth of an inch, although again this distance is not particularly critical. Also, such cuts are parallel to free edge 18 of wall panel 9 with the cut nearest to such edge about three-eighths to one-half of an inch therefrom, although again this distance is not particularly critical. Cover panel 3 overlies and is supported by edge 18 in the set up sealed carton. Although not essential, it is advantageous to join the ends of the parallel cuts 17 by end cuts 21 which also partially penetrate the outside face of panel 9. Thus, the adhesive union area within cuts 17 and 21 is generally rectangular in shape.

To insure when adhesive is applied in the sealing of closure flap 11 to wall panel 9 that adhesive union between the closure fiap and wall panel is only within the adhesive union area 16, the region of the outer face of wall panel 9 about the adhesive union area is provided with an adhesive repellent coating or film 22 which is desirably the ink employed in printing on the outside face of the carton. Such adhesive repellent coating obviates necessity for exact control in registering the adhesive only over the adhesive union area 16 during application of the adhesive, In this connection, it is immaterial whether some of the adhesive repellent coating happens to become applied over the cuts 17 slightly into area 16 as long as a substantial portion of the area between cuts 17 and end cuts 21 remains uncoated by the repellent.

After the closure fiap has been sealed by the adhesive to wall panel 9, and the closure flap 11 is pulled open in the manner indicated in FIG. 6, a narrow strip of material 23 (FIGS. 7 and 8) of the outer face of wall 9 between cuts 17 and end cuts 21 will be removed substantially clean without any peeling of the outer face of wall 9 beyond the cuts, thus leaving the outer face of the wall substantially unmarred otherwise, as can be seen from FIGS. 7 and 10, as no peeling of material will occur between the cut 17 nearest edge 18 of wall 9 and such edge.

Thus, when the carton is reclosed in the manner indi cated in FIG. .10'and wall 9 forms a complete outside face, an unsightly appearance is obviated. Furthermore, the arrangement provides ease of opening, as the removed material 23 is readily pulled from the outside face of wall 9. In this connection, many cartons of the character described are made of paperboard formed by a cylinder machine. As is well known in such cylinder machine application, the paperboard is formed of a plurality of individual layers, thus facilitating clean removal of the material in the adhesive area between the cuts when the carton is opened.

For facilitating pulling closure flap open, it is provided with a transverse line of Weakness in the form of a cutscore line 23'. Such line of weakness forms a readily flexible portion that provides a pull tab 24 that can be readily grasped.

Not only does the described closure flap arrangement provide the advantages pointed out above, but it also decreases cost of production by enabling complete securing of the closure flap to the wall panel in one operation, and minimizing inspection costs which have been previously entailed with other closure flap sealing arrange ments heretofore employed. Although the arrangement is particularly advantageous for securing a closure flap over a hinged carton wall which is adapted to be opened, and then reclosed to form a complete outside face of the carton, the ease with which such arrangement permits clean opening of an adhesively secured closure flap, renders suchconstruction advantageous in any other type of carton wherein the closure flap is adhesively secured to a fixed wall,

I claim:

1. In a paperboard carton blank including a pair of panels having substantially parallel edges adapted to be overlapped, releasable means adapted to secure overlapping faces of said panels together comprising:

a pair of substantially parallel cuts penetrating the overlapping face of one of said panels substantially parallel to the edge thereof,

an adhesive adapted to secure the overlapping faces of said panels together over an area of adhesive union, and

an adhesive repellent coating on a panel adapted to define the area of adhesive union on said one panel as the space between said cuts.

2. A paperboard carton blank scored to provide a plurality of carton wall forming panels including,

a hinged panel at one end of the blank and a hinged closure flap at the opposite end of the blank adapted to engage in overlapping relation in the set-up carton,

an adhesive adapted when said panel and said closure flap are overlapped to secure the overlapping faces together over an area of adhesive union,

a pair of parallel cuts partially penetrating one of said overlapping faces, and

an adhesive repellent coating on one of said panel and said closure flap adapted to define the area of adhesive union on said one face as the space between said cuts.

3. A paperboard carton blank scored to provide a plurality of carton wall forming panels including,

a hinged panel at one end of the blank and a hinged closure flap at the opposite end of the blank adapted to engage in overlapping relation in the set up carton,

an adhesive adapted when said panel and said closure flap are overlapped to secure the overlapping faces together over an area of adhesive union,

a pair of parallel cuts partially penetrating one of said overlapping faces,

an adhesive repellent coating on one of said panel and said closure flap adapted to define the area of adhesive union on said one face as the space between said cuts, and

a tuck-in flap hingedly connected to each end of said hinged panel.

4. In a paperboard carton blank including a pair of panels having substantially parallel edges adapted to be overlapped, releasable means adapted to secure overlapping faces of said panels together comprising;

a pair of substantially parallel cuts partially penetrating the overlapping face of one of said panels substantially parallel to, disposed a distance from, and extending substantially the entire length of the edge thereof;

an adhesive adapted tosecure the overlapping faces of 'said panels together over an area of adhesive union;

and

an adhesive repellent coating on one of the overlapping faces of said panels defining the area of adhesive union on said one panel as the space between said cuts.

Inman Aug. 27, 1957 Brown Mar. 25, 1958 

